Hollow Body Arrangement and Method for Producing Same

ABSTRACT

A building element  1  consists of several individual layers  2, 3, 4  and is designed as a honeycomb construction with partial hollow bodies  26, 27  protruding over the basic construction  16.  Surfaces  10, 11  of adjoining individual layers  2, 3, 4  together form a wall of a small thickness. Individual surfaces  10, 11  of the individual layers  2, 3, 4  have a pre-stressing for improving the connection with adjoining surfaces.

The invention concerns a building element consisting of severalindividual layers and designed as a honeycomb construction with partialhollow bodies protruding over the basic construction, whereby surfacesof adjoining individual layers together form a wall of a small wallthickness.

Such elements are known from DE 100 22 742 A1. In order to bring thedifferent layers together to form a building element, they must beconnected. The starting point of any layer having a hollow body is athin film or membrane, from which such a wall is then created. After anylayer is deformed, the surfaces of the hollow body arrangements andtheir edges result. At the point when two layers are put together, theedge of the hollow body arrangement shows a stable behaviour. On theother hand it has proven problematic that the surfaces of the hollowbody arrangement can turn out to be unstable; they are more or lessborne by the edges.

The present invention therefore sets itself the task of creating aparticularly homogeneous building element consisting of severalindividual layers and designed as a honeycomb construction.

This task is performed through surfaces of the individual layers havinga pre-stressing for improving the connection with adjoining surfaces.

The goal of such a honeycomb arrangement is to create a static/dynamichoneycomb construction, in which materials such as plastics, metals orfibrous composites are interconnected in as stable and lastingly amanner as possible. Here, a number—geared to claim and purpose—ofindividual surfaces of the individual layers are specifically placedunder pre-stressing in order to obtain a connection of the otherwiseunstable surfaces.

One embodiment of the invention intends for the pre-stressing to beapplied through the way in which surfaces of the individual layers aredesigned. In other words, according to this first alternative, thepre-stressing is created to a certain extent from the design of thesurfaces, whether through their geometry, or through a design differentfrom a smooth-walled profile.

According to a proposal for the geometry of the surfaces, theconsideration is to apply the pre-stressing in the form of a convexdeformation pointing inwards or outwards. In the surfaces of the hollowbody arrangements, the necessary energy connection zones are formedwithin a welded connection for the purpose of stabilisation andpre-stressing. These energy connection zones are recesses or bulges ofthe hollow body surfaces as appropriate, which transport the energy flowof the customised welding method accurately into the zones of fusion.Apart from the pre-stressing for stabilising the surfaces for a weldingconnection, the deformations also assume the task of carrying energythanks to targeted welded connection zones with the purpose of makingprecise sub-sections of the surfaces connectable. This solution isparticularly helpful for purposes where large welding gaps have to bebridged.

Alternatively or as an addition to this deformation of the surfaces, itis possible for surfaces of the individual layers to be designed asprofiled. Built-in components or raisings with a pimple or fine stickstructure are what are in mind here. Here, the surfaces also receive thepre-stressing via the convex deformations if necessary. The carrying ofenergy and the welding connection zone however are executed via thepimple or fine stick structure until joining finally takes place. Thesebuilt-in components or raisings can be designed to be chaotic ororderly. A preferred application is in the case of small surfaces andthe bridging of small joining gaps.

A particularly suitable profiling can be recognised in the case ofsurfaces having a lamella-like structure. With this design, an averagejoining gap is bridged and a targeted carrying of energy effected to thelamellas via the energy edge. The surface structures given here form atargeted welding connection zone. The number, shaping and arrangement ofsuch lamellas are dependent on the surfaces (their size in particular)as well as on the joining gap, on the zones to be joined and on theenergy flow of the welding method employed. The lamellas perform thetask of targeted energy carrying right up to the fusion of the tops ofthe surfaces, where they act as a compensation for the joining gap. Theyare preferably used when bridging medium-sized joining gaps.

In addition to the proposal of generating the pre-stress from thesurface of the individual layer, it is intended for the pre-stress to beapplied through a connecting medium introduced between adjoiningsurfaces of the individual layers. If the pre-stressing of the surfacesis effected by means of an appropriate connecting medium, the unstablesurfaces become stressed and the energy flows via this medium. While thezones of fusion of the medium merge, the pre-stressed surfaces relax andconnect up in the zones of fusion with the surfaces of the hollow bodycontour arrangements.

If different materials are interconnected, so-called bonding bridges orbonding supplements are required. Within the intended connections, theseagents are prepared for the more difficult surface to handle, and apreparation on both sides may also be necessary. The bonding bridges ofthe individual layers may be pre-reactive and expand under warmth or theinfluence of moisture for example.

It is also conceivable for the bonding bridge to be profiled orcontribute to the profiling of the existing surfaces, for example in theform of a pimple or fine stick structure on the layers. In this case thebonding bridge pre-stresses the surfaces in order to ensure stabilitywithin the pressure exerted for joining. In this context, the bondingbridge causes the individual layers stacked one into the other to joinvia the hollow bodies or partial hollow bodies.

In order to form a particularly close connection between individuallayers of the same or different material, one measure intends for aflowing net construct to serve as an externally applied connectingmedium. Such connecting media are understood as a thin net which leavesbehind an orderly rough surface. In its raisings, this rough surfacedetermines the zones of fusion of the honeycomb arrangements to beconnected. Such a net can in turn be profiled. This net is designeddepending on the requisite energy to be introduced, which is necessaryfor fusing on the connecting medium in the welding zones.

In order to achieve a sound distribution of the connecting mediumbetween the surfaces or on them, it is intended for a connection supportintroduced as liquid to serve as a connecting medium. After theconnection has been established, the connecting medium should reach theplanned solidity. It is important that the medium is either volatile andthat, within the connection, the surfaces of the hollow body arrangementlying one on top of the other are caused to relax, or that the wallsmerge into one another completely, which leads to higher mass portionshowever. It is to be understood by an ideal chemical connection herethat the surfaces are lying pre-stressed one on top of the other. Thepre-stressing points can be stick-shaped or pimple-like bulges or convexor lamella-like deformations lying one on top of the other. It goeswithout saying that sufficient space must be remaining in order toaccurately displace the chemical connecting medium by way of the joiningpressure and to at the same time develop the intended connecting gap andthus a connection.

Pre-stressing surface structures can also be attached for the purpose ofstabilisation. To this effect, it is recommended for a chemicallyreactive connection support to serve as a connecting medium.

A favourable case is when the chemically reactive connecting medium hasexpanding characteristics.

According to a further embodiment of the invention, it is planned forthe connection of adjoining individual layers to essentially take placevia their edges, their coupling element, their pyramid point and/or thesupporting edges created. The surfaces do not have to receive aconnection here, but the connection can essentially be realised via theinterlocking of the individual layers and the associated hollow bodiesand partial hollow bodies. It is even conceivable here to not botherapplying the pre-stress.

In order to improve the interconnection quality of the surfaces of theindividual layers, it is also practicable for the individual layers tobe manufactured from a liquid-absorbing material.

A further measure plans for individual layers to have air pockets or forindividual layers to have a surface equipped with small bubble-like airpockets. This contributes to increasing the pre-stressing of thesurfaces in such a way that they withstand the joining pressure, inorder to be able to interconnect the hollow bodies or partial hollowbodies.

The building element according to the invention offers a great number offurther possible uses, including when individual layers are designed tobe electrically conductive, either in their complete profile or at leastin the area of their surface.

In this way the cells can be used as air conditioning cells, shockabsorbers, insulators, separators, as ion carriers through the supportof compounds or for comparable processes for the use of energy storage.The key advantage of the building element according to the invention isthe favourable relationship between maximum surface and minimum spacethanks to the nesting. If a battery case is assumed, the subsequentlayers of the construction in the space can be extended at will. Theconnection of greatest possible contact surfaces offered by the entirebuilding element is crucial here.

According to a further embodiment of the invention, it is planned forindividual layers to be made of doughy or liquid moulding materialand/or for adjoining individual layers to merge into a so-calledwet-on-wet connection or dry-wet connection.

The stability of the building elements according to the invention can beincreased considerably through at least the upper-edge-side individuallayer and/or the lower-edge-side individual layer having areinforcement. This can be formed for example by way of a V-shapedstrip, and it is also conceivable for this reinforcement to be used as acontact strip for electrical connections. The reinforcement is insertedin the form of spacer strips for example, in order to ensure a greater,sandwich-like surface loading by the bending forces over the edge-sideinserts.

The proposal for adjoining individual layers to be designed to belinkable with one another is along the same lines. The individual layerspartly interlock in this case, and an immobilisation in the form ofundercuts is also possible. On the one hand, an insulator can berepresented using a levelling compound. On the other hand, this canoffer the exact opposite. It is thus conceivable for the compound to beused as an ion transporter in a battery at the same time.

According to a further advantageous embodiment of the invention, it isplanned for adjoining individual layers to be designed as insulated fromone another. Through the separation of individual layers, cell or layergaps are separately and individually controllable here, in order toensure the above mentioned uses e.g. in the form of air conditioningcells, shock absorbers, insulators or separators. The connection ofgreatest possible contact surfaces offered by the entire buildingelement is crucial here. The individual layers can be merged intodifferent requisite materials and they can be insulated from one anotheroutstandingly in doing so. In the surfaces of the individual layers,conductive fibres or other composites can be introduced, which areneeded in the modern development of nanocells. The supply of oxygen andspecial requisite cells and the isolation from oxygen at an immediatelyadjoining space within such a cell is possible by way of this cellseparation.

As regards the proposal mentioned, it is appropriate for a sealing ringand/or a sealing lip to serve as insulation. The hollow bodies can beheld and insulated from one another via such an all-round sealing ringor an accordingly designed sealing lip.

In addition, the invention concerns a procedure for the production of abuilding element built up of several individual layers and in the formof a honeycomb construction with partial hollow bodies protruding overthe basic construction, where surfaces of adjoining individual layersform a common wall of a small wall thickness and where surfaces of theindividual layers are joined, under pre-stressing, with surfaces ofadjoining individual layers.

This pre-stressing can on the one hand be generated from individualsurfaces of the layers, through a perhaps convex deformation pointinginwards or outwards being applied to these. A profiling is also asuitable measure, e.g. by way of lamella-like structures or suitablebuilt-in components and raisings on the surfaces. As an alternative oraddition to these procedure steps, an external connecting medium can beintroduced between adjoining surfaces of the individual layers, by whichboth a net construct and a chemical connecting medium inserted as aliquid, with expanding characteristics if necessary, are understood.

In other words, surfaces of the individual layers are placed underpre-stress through their arrangement and/or design, or surfaces of theindividual layers are placed under pre-stress through a connectingmedium.

A further measure intends for the individual layers to be sealed in thejoining process via the edge-side individual layer and thelower-edge-side individual layer and for the honeycomb construction tobe placed under a vacuum until the joining process is complete.

A particularly useful variant of the invention intends for theappropriate surfaces of adjoining individual layers to be interconnectedby means of ultrasonic welding. Such a procedure makes a particularlyprecise, lasting and effective connection possible for the individuallayers, and the energy expenditure is comparatively low.

In the course of ultrasonic welding, it is to be noted that very thinfilm layers are welded with one another. A welding energy source that isset too high would inevitably lead to welding burns, and too low awelding energy source setting would lead too incomplete welds. Dependingupon the connection zone, constantly changing welding resistances are tobe reckoned with, due in particular to the manufacturing tolerancecompensation at the honeycombs of the invention in the form of convexsurfaces or other surface pre-stressing. In such a case, each weldingresistance where different connecting tolerances may develop should becalculated before the welding is made.

For this purpose, it is suggested that the resistances of the surfacesto be welded be measured before welding. In the context of thisso-called primary measurement welding, the energy welding source adjuststo the determined value after measurement, in order to avoid weldingburns or faulty connections of the individual surfaces. Thanks to theprimary measurement welding, it is also taken into consideration inparticular that different materials of different densities can beinterconnected. Bonding or connecting bridges must ultimately becreated, in which both materials connect. If different masses havedifferent coefficients of expansion in addition, the materials must beinterconnected in such a way that one of these materials always adaptsto the movement of the other one, without it becoming fatigued ordestroyed. In order to now perform large-scale welding, theinterconnections are either calculated or the manufacturing or expansiontolerances that arise are taken into account before the continuousmanufacturing process and these tolerances are transferred to themanufacturing process.

According to a further proposal, it is planned for a sonotrode to beapplied to the surfaces of the individual layers before ultrasonicwelding takes place. This sonotrode acts on the surfaces to be weldedwith a prescribed force. That is to say, an appropriate tool is broughtinto high-frequency mechanical oscillation, which is then transferred tothe surfaces to be welded. The sonotrode must act on the surfaces to bewelded with a given force before this ultrasonic welding takes place.Since the surfaces may already be pre-stressed one beside the other, thesurfaces are reinforced by pressing one down on the other, so that thereis no hollowness between them at the time of welding pressing. Since allplastics ultimately have an elastic structure, the surfaces slacken alittle after welding. In order to calculate this beforehand, a specialconvex sonotrode is used for each individual material. This convexitydepends on the material, on the size of the surface to be processed, thematerial thickness and/or the material executions. Such sonotrodes cantherefore be used for the surface welding of things such as paper,fibres, metals, non-ferrous metals or plastics.

Further details and advantages of the object of invention are given inthe following description of the associated drawing, in which apreferential execution example with the necessary details and componentsare shown:

FIG. 1 Shows a building element with an interior honeycomb construction,

FIG. 2 Shows a hollow body in the form of a double pyramid from theside,

FIG. 3 Shows the double pyramid-shaped hollow body from above,

FIG. 4 Shows a perspective view of the interior of an edge-sideindividual layer,

FIG. 5 Shows an exploded drawing of a five-part building element,

FIG. 6 Shows a partial hollow body partly under pre-stress,

FIG. 7 Shows a hollow body with a lamella-like structure,

FIG. 8 Shows a modification to FIG. 7,

FIG. 9 Shows a building element where the individual layers interlink,

FIG. 10 Shows a sectional view of the picture in FIG. 9,

FIG. 11 Shows a variant of FIG. 9,

FIG. 12 Shows a variant of FIG. 9,

FIG. 13 Shows a sectional view of the picture in FIG. 12,

FIG. 14 Shows a single cell of a building element

FIG. 15 Shows a variant of FIG. 14.

FIG. 1 shows a building element 1 in its final state. The upperedge-side individual layer 2 is partly opened in order to make thehoneycomb construction 3 visible, which is supported on the one hand atthe upper edge-side individual layer 2 and on the other hand at thelower edge-side individual layer 4. The honeycomb construction 3 isshown here in a simplified manner. The side edge 5 of the buildingelement 1 is shown in the form of a smooth plane, as is also theedge-side individual layer 2.

The honeycomb construction consists of a great number of individuallayers with hollow bodies and partial hollow bodies. Both the edge-sideindividual layer 2 and the edge-side individual layer 4 with thehoneycomb construction 3 joined in between consist of honeycomb partplates 17 of a small wall thickness.

The individual hollow bodies 7, 8, 9 according to FIG. 2 usually formpyramids 14, 14′ or mirror-image double pyramids 19, whereby theindividual segments serve 20, 21 serve for achieving and securing analtogether flat support of the individual elements of the honeycombconstruction against one another. The pyramids 14 or mirror-image doublepyramids 19 are particularly well-suited for a so plane support of theindividual elements, since surfaces 10, 11, accordingly offset to oneanother, are available and are also large enough for the forces actingon the building element 1 to be reliably absorbed and passed on. The twopyramids 14, 14′ are connected with one another via the coupling element22; the central axis 30 separates both building elements or they areconnected with one another along this central axis 30. At the points 12of the individual pyramids 14, 14′ flattenings 13 are intended in orderto make an additional sound support of the individual parts orindividual elements possible on the edge strips 31 or the spacer strips18 or the basic construction 16.

While the separation line shown in FIG. 2 joins the two pyramids 14, 14′into a mirror-image double pyramid 19, according to FIG. 3 the centralaxis 30 is the separation line at the same time, which leads through theflattened points 12. It is not clear however that the edges 15, 15′ canbe designed as perforated or cut open in order to make bending therelevant individual layer as well as the entire building element 1possible without all too great forces having to be applied.

An edge-side individual layer 2 and 4 is represented in FIG. 4, whichhas hollow bodies 7, 8 and pyramids on its interior 28 respectively. Theindividual pyramids 14 all have the same dimensions and are connectedwith one another via the basic construction 16. The latter forms thespacer strips 18 at the same time, which ensure on the one hand that theindividual pyramids 14 are each arranged at the same distance from oneanother and which also ensure that the partial hollow bodies 26, 27 and7, 8, 9, created when each of the individual layers are pushed together,can support themselves on this spacer strip 12 with their points 12.

FIG. 5 shows a building element which is built up of five individuallayers 2, 4, 23, 24, 25 altogether. It is well illustrated here how,using the building element 1 according to the invention, an enormoussurface can be realised which has a minimal space requirement thanks tothe arrangement of the individual cells. Uses as a battery case forexample are therefore quite an obvious choice. The edge-side individuallayers are designated with the references 2 and 4, while the middleindividual layer 25 serves, with its partial hollow bodies 26 and 27protruding on both sides, as a coupling link for the individual layers23, 24 and the edge-side individual layers 2, 4 at the same time. It canbe seen that the middle individual layer 25 has protruding pyramids 14and 14′ towards both sides, in order to make the interlocking orconnection with the accordingly designed individual layers 23 and 24possible, during which additional hollow bodies 7, 8, 9 and partialhollow bodies 26, 27 are then also created.

In FIG. 6, a hollow body is represented on the surfaces 10, 11 of whichpre-stressing deformations are indicated with the reference 41 and 42.These serve for the pre-stressing for the surfaces 10, 11 that come intocontact with one another of the hollow bodies 7, 8, 9 and partial hollowbodies 26, 27. The design of the contact surfaces with regard to thepre-stressing deformations 41, 42 on the surfaces 10, 11 depend on theone hand on the size of these surfaces 10, 11 in terms of theirsupporting characteristics, and on the other hand on the kind of joiningand the energy to be expended.

In the representation according to FIG. 7, surface structures 39, 40 areshown in the form of lamellas on the hollow body 7—on its surfaces 10,11 to be more precise. These are particularly suitable in the case ofinaccessible welding methods. The energy edge is designated as 43.

In FIG. 8, a hollow body with surfaces 10, 10′ is represented with aprofiling in the form of a pimple structure 36 and a stick structure 37,as they are used for bridging small joining gaps and in the case ofsmall surfaces. Both surface structures can be formed in the shaping ofthe hollow bodies and partial hollow bodies. They can however also beapplied later on via a flowing net-like connection support. Such surfacestructures are used in the gap displacement principle with liquid orsolid connecting media. They have the task of reinforcing smallersurfaces in order to stabilise these after the joining contact pressure.They form the zones of fusion and energy for the welding method and alsodetermine the connection zones in doing so.

FIGS. 9 and 10 show a building element where the individual layers 23,24′ and 24 interlink. A V-shaped strip 45 forms a reinforcement 44. Itis also conceivable for the reinforcement 44 of the V-shaped strip 45 tobe used as a contact strip for electrical connections. In this way thecell 52 can be used as a separator and the V-shaped strips 45, 45′ canbe used as electrical conductors or poles.

A building element 1 is represented in FIG. 11 where the individuallayers 23, 24 interlink. The individual layers 23, 24, 24′ can also beimmobilised via the undercut 46. The individual layers 23, 24 can beinsulated and separated well by means of a sealing lip or a sealing ring47.

A five-layer building element 1 is shown in FIGS. 12 and 13, where theindividual layers 23, 24′, 24 and 33 interlink. The pole 48 connectsthese individual layers, which can be extended at will here byinterconnecting them loosely or as laminated individual layers 50. Inthe separator 52, any masses 49 can be introduced, which are suitablefor various uses.

Thanks to the separation of individual layers, the cells of the spacesbetween layers can be controlled separately and individually, forexample in connection with the use of a battery case. Owing to thesupport of the masses 49 and 51, the cells can also be used as ioncarriers or for comparable processes, which are needed for the use ofenergy storage. The connection of greatest possible contact surfacesoffered by the entire building element is crucial here. The individuallayers can be merged into different requisite materials here and can beinsulated from one another outstandingly in this way.

Finally, FIGS. 14 and 15 show a single cell of a building element. Thepole 48 offers a connecting latch in which the individual layers 23 and24′ are held and connected. The individual layers 23, 24′ and 24 form aninsulator here with the individual layer 33, which can also assumeelectrical conduction functions at the same time. The levelling compound51 can represent this insulator on the one hand, but the exact oppositeis also conceivable. For example, the mass 51 can be used as an iontransporter in a battery at the same time.

1. Building element (1), which consists of several individual layers (2,3, 4) and is designed as a honeycomb construction with partial hollowbodies (26, 27) protruding over the basic construction (16), wherebysurfaces (10, 11) of adjoining individual layers (2, 3, 4) together forma wall of a small thickness and have a pre-stressing for improving theconnection with adjoining surfaces, wherein at least the upper edge-sideindividual layer (2) and/or the lower edge-side individual layer (4)have a reinforcement (44) that is designed as a contact strip forelectrical connections.
 2. Building element in accordance with claim 1,wherein the pre-stressing is applied by the design of surfaces (10, 11)of the individual layers (2, 3, 4).
 3. Building element in accordancewith claim 2, wherein the pre-stressing is applied in the form of aconvex deformation pointing inwards or outwards (41, 42).
 4. Buildingelement in accordance with claim 2, wherein surfaces (10) of theindividual layers (2, 3, 4) are designed as profiled.
 5. Buildingelement in accordance with claim 4, wherein surfaces (10) have alamella-like structure.
 6. Building element in accordance with claim 1,wherein the pre-stressing is applied through a connecting mediumintroduced between adjoining surfaces (10) of the individual layers (2,3, 4).
 7. Building element in accordance with claim 6, wherein a flowingnet construct serves as an externally applied connecting medium. 8.Building element in accordance with claim 6, wherein a connectionsupport introduced as a liquid serves as connecting medium.
 9. Buildingelement in accordance with claim 6, wherein a chemically reactiveconnection support serves as a connecting medium.
 10. Building elementin accordance with claim 7, wherein the chemically reactive connectingmedium has expanding characteristics.
 11. Building element in accordancewith claim 1, wherein the connection of adjoining individual layers isessentially made via the edges (15) of the latter, their couplingelement (22), their pyramid point (12) and/or the resulting supportedges.
 12. Building element in accordance with claim 1, whereinindividual layers (2, 3, 4) are manufactured from a liquid-absorbingmaterial.
 13. Building element in accordance with claim 1, whereinindividual layers (2, 3, 4) have air pockets.
 14. Building element inaccordance with claim 1, wherein individual layers (2, 3, 4) aredesigned to be electrically conductive.
 15. Building element inaccordance with claim 1, wherein individual layers (2, 3, 4) are made ofdoughy or liquid moulding material and/or that adjoining individuallayers (2, 3, 4) merge into a so-called wet-on-wet connection or adry-wet connection.
 16. (canceled)
 17. Building element in accordancewith claim 1, wherein adjoining individual layers (23, 24) are designedto be linkable with one another.
 18. Building element in accordance withclaim 1, wherein adjoining individual layers (23, 24) are designed to beinsulated from one another.
 19. Building element in accordance withclaim 18, wherein a sealing ring (47) and/or a sealing lip serves asinsulation. 20-26. (canceled)